Mad as a Hatter: Revisiting Primary Hyperparathyroidism in the Elderly

Primary Hyperparathyroidism (PHPT) is a common endocrine disorder and its prevalence increases with age. It is characterized by an abnormal regulation of calcium secretion resulting from increased parathyroid hormone (PTH) levels. Symptomatic PHPT can present with neuropsychiatric symptoms including depression, anxiety, cognitive decline, psychosis, and agitation. In patients with longstanding PHPT with mildly elevated serum calcium, acute change in personality can be overlooked to be related to rising serum calcium.